Surface grinder



May 27, 1952 H. r. RurHl-:RFoRD SURFACE GRINDER 2 SHEETS-SHEET l FiledSept, 20, 1949 i/IZ H. T. RUTHERFORD SURFACE GRINDER May 27, 1952 2SHEETS-SHEET 2 Filed Sept. 20, 1949 r x r 1 F/ ci', 3',

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Patented May 27, 1952 UNITED STATES PATENT i OFFICE SURFACE GRINDERHarry T. Rutherford, Baltimore, Md. Application September 20, 1949,Serial No. 116,654 1 Claim. (Cl. 51-102) The present invention relatesgenerally to grinders and in particular to what is known as surfacegrinders. rlhis type grinder is especially adapted to the grinding of atsurfaces such as cylinder heads and blocks, although they are notlimited to this specific use, and may be used for many other types ofwork requiring a smooth fiat surface.

There are in the art various type surface grinders which work on adifferent principle. Many of these grinders leave on the surface aparticular mark or unevenness known in the trade as "grain marks, etc.Much of this unevenness and marking comes from the neness or coarsenessof the wheel. However, it most generally comes from the speed of thecutting stone and the manner in which the stone or grinding wheel comesin contact with the work. Therefore, it is the desire to improve thistype surface grinder that prompted the development of this apparatus.

The present trend of automotive manufacturers is to use a very thinsteel sheet head gasket and the cylinder head must be substantiallyflat, or be within small tolerances of being flat, to prevent leakagebetween the head and the cylinder block with the use of these gaskets.Therefore, the regrinding of cylinder heads has become more and more anecessity. It is also of importance to have the ground surface of thehead of such a character that will effect the maximum amount of bondbetween the head and the block when the head is fastened into place.

Y One object of the invention is to provide a simple and practicalmachine having a minimum number of moving parts and capable of finishinga fiat surface within close tolerances.

Another object of the invention is to provide an apparatus of this typein which a higher speed grinding wheel may be employed.

Still another object of the invention is to provide a surface grinderupon which articles of considerable range in size may be ground.

With the above and other objects in View, the invention consists of thenovel construction, combination and arrangement of parts as shown in theaccompanying drawings and described in the following specifications inwhich:

Figure 1 is a plan view of the machine.

Figure 2 is a side elevation of the same.

Figure 3 is an enlarged fragmentary sectional view taken along the line3-3 of Figure 1.

Figure 4 is an enlarged sectional view taken along the line 4 4 ofFigure 1.

Figure 5 is a fragmentary detailed view of the grinding wheel bearingand its adjustment.

In the specications like reference characters are used. to designate thesame and similar parts throughout the several views Where practical.

The machine is normally provided with a ba-se I0 supported uponappropriate legs or supports I2. Positioned upon the base is a table, orwork support I4, which is provided an-upper surface. The upper surfaceof the table I4 is divided into two portions I4 and I4". These portionsare in parallel planes of approximately twothousandths of an inchdifference in height, and will be more specifically describedhereinafter. Extending along each side of the upper surface of the tableare side members, or work guides, I6 and I8 for reinforcing the tableand serving as a guide for defining a path over which the articles beingground are passed. However, these side members, or work guides, may havein addition an adjustable work guide 20 which is carried by the sidemember as shown in Figures 1 and 4. The adjustment of the guide 2i) iseffected by the members 22, 24, 26 and 2S which are adapted to passthrough appropriate apertures in the member I8 and are secured in theselected position by the set screws 3G, 32, 34 and 35. The work support,or table, may be constructed by casting, or by other well-knownmanufacturing methods.

The table is normally of rectangular shape, but may be of any form bestsuited for the particular operation. The work guides, being either themembers I 6, I8, or the adjustable gauge 20, are adapted to designatethe direction and/or the path the work is to take over the upper smoothsurface of the table.

Positioned diagonally across the table is a suitable grinder, such as acylindrical stone 49 of small diameter, which is adjustable relative tothe upper surface of the table. The stone is supported upon a suitableshaft 42 and is carried in bearings 44 and 46 on each side of the table.These bearings are supported in journals 48 and 50 which in turn areadjustably supported in frames 52 and 54. The grinder is adjusted bymeans of the hand wheel 56, which is iixedly secured to one end of ashaft 53. The shaft 58 is threadably receivable within an aperturewithin the lower portion of the frame 52. The opposite end of the shaftis rotatably secured to the journal 48 and is adapted to move thejournal within the frame as the shaft is rotated. Also secured to theshaft 58 is a sprocket 60 about which a chain 62 is engaged. The chainextends to the opposite side beneath the table and engages a similarsprocket G, which, in turn, is fixedly secured to the shaft 69. Theoperation and construction of the shaft G9 is substantially the same asthat just described for the shaft 58 and operates the journal 58 withinthe frame 54 in substantially the same manner. With this arrangement,both the hearings 45 and 4G are adjusted an equal amount by operatingthe hand wheel 59.

The stone is adapted to be rotated at a relatively high speed, which ispossible because of its small diameter. The grinder is driven in anysuitable manner. The preferred driving means consists of a motor 'I9which is set at an angle to the table and supported upon the frame ofthe machine so that its driving shaft 'H is parallel with the stoneshaft 152. On the shafts e2 and 1I are V-pulleys l2 and 'ill over whichis carried a V-belt 1S. On the slack side of the belt is an idler '59.The length of the belt is such as to allow for adjusting the grindingstone up and down relative to the upper surface of the table, the idler7B taking up the slack.

There is provided across the table a narrow diagonal opening throughwhich the stone is projected slightly above the upper surface of thetable. '1" his opening is very narrow as the height of the stone abovethe table amounts to only a few thousandths of an inch. The edges Id" ofthe table are arcuated about the grinding stone as shown in Figure 3 inorder to keep the opening in the table at a minimum width.

Referring in particular to Figure 3, the table, or work support I4consists of two portions Hi and I". The portion lli is that portion ofthe table on the feed side of the grinding wheel, and the portion it isthat portion of the table beyond the wheel in the direction of the feed.The work passes over the table as indicated by the arrow from the lowerportion of the table, or bed l' to the higher portion i5". Thisdifference in height, or step, in the table after the cut of thegrinding wheel on the work is very important. The stone is turned at avery high speed and is normally set to cut approximately two-thousandthsof an inch from the work as it passes along and over the table. Theportion i4 of the table is of substantially the same height above thetable portion l as the uppermost portion of the grinding stone(approximately two-thousandths of an inch) in order that the work willslide along the higher surface of the table after the cut has been madeand be supported thereby; otherwise, the work would rook about the stoneas it progressed along the table.

As stated, the stone is positioned diagonally across the table and at anangle of approximately thirty to thirty-five degrees with aperpendicular line to the path of the work. In operation, the stone isfirst dressed in order that it will have a cutting surface parallel withthe upper surface of the table. rlhe stone is then moved by itsadjusting means to a point where its highest cutting line will besubstantially in a plane with the upper portion lli" of the table. Thestone is then rotated in the direction of the arrow as shown in Figure3. When the stone is rotating at its proper speed, the work 89 (in theform of a cylinder head) is moved in the direction of the arrow over thelow table portion I4' against the grinding stone 59, as shown at 8|,where a predetermined amount of its surface will be removed, that is,the difference in the heights of the two table portions lli and It". Asthe work is moved over the stone, the ground portion of the work will beof such height as to slidably rest upon the portion ifi and prevent thework from dropping down behind the stone.

While the invention has been described in a specific form, it is notintended to be a limitation of the broad application thereof as thescope of the invention is best defined in the following claim.

I claim:

1n a machine for grinding engine heads and the like, the combination ofan elongated table having an upper surface and a narrow diagonal openingextending therethrough, the upper surface of the table being formed inan upper and lower portion extending outwardly from each side of thediagonal opening and iixedly secured in two horizontally spaced parallelplanes, the difference in height of the upper surfaces of the twoportions being not greater than .G92 of an inch, a single high speedcylindrical grinding element of relatively small diameter mounted withinthe diagonahopening of the table having its axis parallel with the uppersurface thereof and adapted to have its upper portion rotated in thedirection of the lower portion of the table, the grinding element havinga supporting shaft extending entirely throughout the cylindrical axis ofthe grinding element, a bearing at each end of the diagonal slot toreceive the said shaft, vertically fixed guideways extending downwardlyfrom the table for slidably receiving the bearings, means locatedbeneath the table and extending between the bearings for simultaneouslyadjusting both the bearing relatively to their respective guideways andmeans mounted on the said shaft for rotating the said grinding element,all substantially as shown and described.

HARRY T. RUTHERFORD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 926,101 Connet June 29, 19991,722,724 Wegner July 30, 1929 2,169,954 King Aug. 15, 1939 2,318,052Bramble et al May 4, 19d- 3 2,337,718 Hoppes Dec. 28, 1943 2,463,750Curtin Mar. 8, 1949 2,483,277 Hamilton Sept. 27, 1949 2,483,369 Louconyet al Sept. 27, 1949 FOREIGN PATENTS Number Country Date 317,265 GreatBritain Aug. 15, 1929 633,399 France Oct. 24, 1927 OTHER REFERENCES Woodand Iron, published June 15, 1886.

